1. Field of the Invention
This invention relates to an IC retainer in an IC socket, in which an IC or an IC carrier is retained in the IC socket for maintaining a reliable electric connection.
2. Brief Description of the Prior Art
Japanese Laid-Open Patent Application No. Hei 3-289077 teaches an IC retainer comprising a lock lever which is locked to and unlocked from an IC carrier in accordance with upward and downward motion of a cover, a turnable lever for transforming the upward and downward motion of the cover to upward and downward motion of the lock lever, and a groove cam means for shifting the lock lever to a backward unlocking position when the lock lever is moved upwardly and to a forward locking position when the lock lever is moved downwardly.
In order appropriately unlock the lock lever from the IC carrier, it is necessary for the operator to turn the lock lever to the backward unlocking position slightly above the engaging (or locking) surface. Also, in order to apply a depression force (to obtain a contacting pressure) to the IC carrier by bringing the lock lever into appropriate engagement with an edge portion of the IC carrier, it is necessary for the operator to lower the lever after the IC carrier is turned to a higher forward position.
According to the teaching of the prior art, as a means for moving the lock lever upwardly and downwardly, one end portion of the turnable lever and the cover is linked by means of a shaft and an elongate slot, the linking portion is raised under the effect of a spring biasing the cover upwardly, so that one end of the turnable lever will be raised, and the linking portion is depressed by depressing the cover against the biasing force of the spring, so that one end of the turnable lever will be lowered, thereby transforming the upward and downward motion of the cover to the upward and downward motion of the lock lever which is turnably axially supported by the other end of the turnable lever.
According to the teaching of this prior art, the resilient force of the spring acting to push up the cover is transmitted to the lock lever via the linking portion and the turnable lever, so that an upward and downward motion, against the effect of the spring, of the lock lever as well as a downward motion, following the effect of the spring, of the lock lever can be obtained.
However, in the above prior art, since the cover is pushed up under the effect of the spring to resiliently connect the cover and the turnable lever to each other, it is necessary to link one end of the turnable lever to the cover by means of the shaft and the elongate slot in order to have the turnable lever appropriately follow the upward and downward motion of the cover.
That is to say, if the turnable lever and the cover are not linked together, it becomes impossible to raise one end of the turnable lever when the cover is moved upwardly, with the result that a required action of the lock lever can not be obtained.
Further, since the spring force urging the cover upwardly acts on the lock lever via the linking portion and the turnable lever so that the lock lever is lowered, the turning motion of the turnable lever is not smoothly transformed to the vertical downward motion of the lock lever. As a result, the depression force applied to the IC carrier by the lock lever is not sufficient. Consequently, it gives rise to the problems that reliability of contact is lowered and poor electrical connection occurs.
Furthermore, in the prior art, since it is absolutely necessary to link the cover and the turnable lever to each other, manufacturing and assembling are difficult, and play is liable to occur between the shaft and the elongate slot.
The present invention has been accomplished in view of the above-mentioned problems inherent in the prior art.